Electrofusion fitting

Abstract

The invention involves an electrofusion pipe fitting. The fitting has a body having a pipe-receiving aperture. An electric heating element surrounds the aperture. The fitting has a thermochromic indicator at an axial end.

1 . An electrofusion pipe fitting component comprising:
 a body having a pipe-receiving aperture;   an electric heating element surrounding the aperture; and   a thermochromic indicator at an axial end of the component.   
     
     
         2 . The fitting of  claim 1  wherein:
 the body is formed of a fusion collar. 
 
     
     
         3 . The fitting of  claim 1  wherein:
 the body is formed of a molded non-metallic material. 
 
     
     
         4 . The fitting of  claim 1  wherein:
 the heating element comprises a coil at least partially embedded in the body. 
 
     
     
         5 . The fitting of  claim 1  wherein:
 the thermochromic indicator is a thermochromic liquid crystal based coating. 
 
     
     
         6 . The fitting of  claim 5  wherein:
 the thermochromic liquid crystal comprises a cholesteric thermochromic liquid crystal material. 
 
     
     
         7 . The fitting of  claim 5  wherein:
 the thermochromic liquid crystal comprises TiO 2 . 
 
     
     
         8 . The fitting of  claim 5  wherein:
 the thermochromic liquid crystal comprises hindered amine light stabilizer. 
 
     
     
         9 . The fitting of  claim 1  wherein:
 the thermochromic indicator is positioned on a connector tab. 
 
     
     
         10 . The fitting of  claim 1  wherein:
 the thermochromic indicator is configured to change color at a temperature of 59-72 C. 
 
     
     
         11 . A method for manufacturing the fitting of  claim 1 , the method comprising:
 molding the body over the heating element; and   applying the thermochromic indicator to the body.   
     
     
         12 . The method of  claim 11  wherein:
 the applying comprises applying in a fluid form. 
 
     
     
         13 . A method for forming a joint between a pipe fitting and a connected member, the method comprising:
 inserting an insertion portion of the connected member into an aperture of a body of the fitting;   energizing a heating element of the fitting so as to:
 electrofuse the body of the fitting to the insertion portion; and 
 change color of a thermochromic indicator at an axial end of the fitting. 
   
     
     
         14 . The method of  claim 13  wherein:
 the mating member is a pipe and the insertion portion is an end portion of the pipe or a spigot portion of a second fitting. 
 
     
     
         15 . The method of  claim 13  further comprising:
 applying the thermochromic indicator to the fitting. 
 
     
     
         16 . A piping system joint comprising:
 a first member;   a second member fused to the first member;   an electric heating element at least partially embedded within the first member and/or second member; and   a thermochromic indicator at an axial end of one of the first member and the second member and in a color-changed post-heating condition.